U.S. patent number 5,195,994 [Application Number 07/573,018] was granted by the patent office on 1993-03-23 for coupling for joining flexible tubing for medical purposes.
Invention is credited to Franz A. Dieringer.
United States Patent |
5,195,994 |
Dieringer |
March 23, 1993 |
Coupling for joining flexible tubing for medical purposes
Abstract
A coupling for connecting hose lines for medical purposes
including a first coupling member (1) having supported therein an
axially shiftable hollow plug (2) with a tapered connector (16) for
connecting thereto a first hose length and extending in its
operating position through a sponge member (9) soaked with a
disinfectant and capable of being pierced through a diaphragm (11)
for coupling with a second coupling member (5), both coupling
members (1, 5) being releasably connected together. Hollow plug (2)
consists of outer and inner parts (3, 4) concentrically and
telescopically arranged relative to each other so that both parts
(3, 4) of the plug (2) are relatively axially and rotatably
shiftable whereby a transverse flow passage (19) in outer part (3)
is closed by inner part (4) or communicates with channel grooves
(20) in the inner part to facilitate flow through the coupling.
Inventors: |
Dieringer; Franz A. (A-1040
Vienna, AT) |
Family
ID: |
3481623 |
Appl.
No.: |
07/573,018 |
Filed: |
November 7, 1990 |
PCT
Filed: |
January 19, 1990 |
PCT No.: |
PCT/AT90/00008 |
371
Date: |
November 07, 1990 |
102(e)
Date: |
November 07, 1990 |
PCT
Pub. No.: |
WO90/07953 |
PCT
Pub. Date: |
July 26, 1990 |
Foreign Application Priority Data
Current U.S.
Class: |
604/534; 604/326;
128/912; 604/256; 604/905 |
Current CPC
Class: |
A61M
39/162 (20130101); Y10S 128/912 (20130101); Y10S
604/905 (20130101); A61M 2039/1027 (20130101) |
Current International
Class: |
A61M
39/00 (20060101); A61M 39/16 (20060101); A61M
025/00 () |
Field of
Search: |
;604/236-237,280,283,164,905,326,256,244,249,167,166,170,246,748
;128/912,766 ;285/34 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
386523 |
|
Sep 1988 |
|
AT |
|
0080379 |
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Jun 1983 |
|
EP |
|
0116986 |
|
Aug 1984 |
|
EP |
|
Primary Examiner: Yasko; John D.
Assistant Examiner: Stright, Jr.; Ronald
Attorney, Agent or Firm: Jacobson, Price, Holman &
Stern
Claims
What is claimed is:
1. In a coupling having a longitudinally extending axis for
connecting hose conduits for medical purposes including a first
coupling member, a second coupling member releasably connected to
said first coupling member, second hose connecting means for
connecting said first and second coupling members to a second hose
length, a sponge member soaked with a disinfectant within said
first coupling member, a diaphragm connected within said second
coupling member, and a hollow plug axially movable within said
coupling members and extending in the operating position thereof
through said sponge member and piercing through said diaphragm for
coupling a first hose length to said second hose length through
said coupling, the improvement comprising:
said second hose connecting means being on said second coupling
member;
means for supporting said hollow plug on said first coupling member
for relative axial movement therein;
said hollow plug comprising an outer part and an inner part
telescopically and rotatably disposed within and relatively to said
outer part; cooperating sealing means on said inner and outer parts
for sealing said inner and outer parts with respect to each
other;
a plurality of axially extending channels on said inner part;
at least one radial perforation in said inner part extending
radially relative to and communicating with said axially extending
channels;
first hose connecting means for said first hose length on said
inner part and communicating with said at least one radial
perforation; and
radially extending openings in said outer part, said radial
openings being closed by said inner part when said outer part is in
a first relative rotated position with respect to said inner part,
and in communication with said channels and said at least one
radial perforation through said channels when said outer part is in
a second position of rotation with respect to said inner part.
2. A coupling as claimed in claim 1 and further comprising:
a sealing disc mounted in said second coupling member for sealing
engagement with said outer part of said plug when said plug is
moved axially through said second coupling member.
3. A coupling as claimed in claim 1 and further comprising:
a further diaphragm perforatable by said plug mounted in said
second coupling member for sealing engagement with said outer part
of said plug when said plug is moved axially through said second
coupling member.
4. A coupling as claimed in claim 1 and further comprising:
a guide slot in said first coupling member having a first part
extending longitudinally and substantially parallel to said
longitudinal axis from a proximal end remote from said diaphragm to
a distal end, and a second part extending circumferentially from
said distal end of said first part of said guide slot; and
an actuating protrusion extending radially from said outer part of
said plug through said guide slot for sliding engagement therein so
that said protrusion is manipulable for moving said plug axially in
said first part of said slot in said coupling member and rotatably
in said second part for rotating said outer part between the closed
position of said radial openings and said position in communication
with said channels in said inner part.
5. A coupling as claimed in claim 1 and further comprising:
said second host connecting means on said second coupling member
comprising a connecting element positioned eccentrically relative
to said longitudinal axis;
a vent opening in said second coupling member located coaxially
with said longitudinal axis; and
means on said outer part of said plug engageable with said vent
opening for closing said vent opening when said plug is moved
axially through said sponge member and diaphragm in the coupled
position for use.
6. A coupling as claimed in claim 5 wherein:
said means for closing said vent opening comprises a sealing
protrusion on said one end of said outer part of said plug
engageable in sealing relationship within said vent opening.
7. A coupling as claimed in claim 1 and further comprising:
a base disc on one end of said outer part of said plug adjacent
said first hose connecting means; and
claw member on said inner part of said plug adjacent said first
hose connecting means engageable with said base disc for retaining
said inner part in said outer part.
8. A coupling as claimed in claim 7 and further comprising;
a hollow conical sealing surface on said outer part extending
through said base disc on said outer part;
said claw members being circumferentially spaced radially outwardly
relative to said longitudinal axis; and
a cooperating conical sealing surface on said inner part adjacent
to and radially inwardly of said claw members for sealing
engagement with said hollow conical sealing surface on said outer
part when said inner and outer parts are connected together.
9. A coupling as claimed in claim 8 and further comprising:
an annular lip sealing means interposed between said inner part and
said outer part adjacent said conical sealing surfaces.
10. A coupling as claimed in claim 1 and further comprising means
for supporting said inner part of said plug within said outer part
of said plug so that said outer part and inner part are axially
moveable together and rotatably movable with respect to each
other.
11. A coupling as claimed in claim 10 and further comprising:
at least one absorbing insert member in the form of an annular disc
of foamed material within said second coupling part for engagement
with said plug when said plug is moved axially through said
diaphragm and sponge member for functioning as a stripping disc for
wiping off and absorbing disinfectant material on the other surface
of said plug.
12. A coupling as claimed in claim 11 and further comprising:
said second hose connecting means on said second coupling member
comprising a connecting element positioned eccentrically relative
to said longitudinal axis;
a vent opening in said second coupling member located coaxially
with said longitudinal axis; and
means on said outer part of said plug engageable with said vent
opening for closing said vent opening when said plug is moved
axially through said sponge member and diaphragm in the coupled
position for use.
13. A coupling as claimed in claim 10 and further comprising:
said second host connecting means on said second coupling member
comprising a connecting element positioned eccentrically relative
to said longitudinal axis;
a vent opening in said second coupling member located coaxially
with said longitudinal axis; and
means on said outer part of said plug engageable with said vent
opening for closing said vent opening when said plug is moved
axially through said sponge member and diaphragm in the coupled
position for use.
14. A coupling as claimed in claim 1 and further comprising:
at least one absorbing insert member in the form of an annular disc
of foamed material within said second coupling part for engagement
with said plug when said plug is moved axially through said
diaphragm and sponge member for functioning as a stripping disc for
wiping off and absorbing disinfectant material on the outer surface
of said plug.
15. A coupling as claimed in claim 14 and further comprising:
said second hose connecting means on said second coupling member
comprising a connecting element positioned eccentrically relative
to said longitudinal axis;
a vent opening in said second coupling member located coaxially
with said longitudinal axis; and
means on said outer part of said plug engageable with said vent
opening for closing said vent opening when said plug is moved
axially through said sponge member and diaphragm in the coupled
position for use.
16. A coupling as claimed in claim 15 and further comprising a
separate mounting member insertable within said second coupling
member for supporting said diaphragm and the stripper disc within
said second coupling member.
17. A coupling as claimed in claim 14 and further comprising:
a further diaphragm perforatable by said plug mounted in said
second coupling member for sealing engagement with said outer part
of said plug when said plug is moved axially through said second
coupling member.
18. A coupling as claimed in claim 17 and further comprising:
a base disc on one end of said outer part of said plug adjacent
said first hose connecting means; and
claw members on said inner part of said plug adjacent said first
hose connecting means engageable with said base disc for retaining
said inner part in said outer part.
19. A coupling as claimed in claim 14 and further comprising:
a sealing disc mounted in said second coupling member for sealing
engagement with said outer part of said plug when said plug is
moved axially through said second coupling member.
20. A coupling as claimed in claim 14 and further comprising a
separate mounting member insertable within said second coupling
member for supporting said diaphragm and the stripper disc within
said second coupling member.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention refers to a coupling for connecting hose conduits for
medical purposes, and mole particularly to such a coupling
including a first coupling member having supported therein an
axially shiftable hollow plug for connecting thereto a first hose
length and extending in its operating position through a sponge
member capable of being soaked with a disinfectant and being
capable of being pierced through a diaphragm for coupling to a
second hose length, the diaphragm being connected with a second
coupling member and both coupling members being releasably
connected one with the other.
2. Description of the Prior Art
A device of the initially mentioned type has become known from
German Patent Document AT-PS 386 523. In the known sterile
connection, a plug is supported within a coupling member for being
axially shiftable, and, when axially shifting the plug, the free
end of the plug located remote from the hose connection is moved
through elastically deformable insects, in particular bodies of
foamed material, being impregnated with a disinfectant. In the
known arrangement there is used in an advantageous manner a
multipart insert member consisting of foamed material and receiving
the disinfectant, so that it is possible to permanently make
available within this coupling member a minimum amount of
disinfectant and to replenish the required amount of disinfectant
by means of the second removable body of foamed material when using
the device several times. In this case, the bodies of foamed
material have an opening being concentric relative to the axis of
the plug and are, when shifting the plug in the axial direction,
pressed against the outer surface of the plug under elastic
compression. In this known arrangement, the second coupling member
to be coupled with the first coupling member has the sole function
to close in a sterile manner the equipment, such as for example in
fusion bottles or the like, connected to said coupling member, for
which purpose there is connected with the second coupling member a
perforable diaphragm.
The hose line connected with the plug has, for example, been
directly connected with the patient via a catheter and could remain
in permanent connection with such a catheter when in fusion
bottles,, bags or the like had to be interchanged. For such an
interchange it was only necessary to move the plug back into its
retracted position to make sure that any risk of infection is
reduced when interchanging the infusion equipment or the like. The
second coupling member could be brought into a conductive
connection with the infusion equipment, in particular infusion
bottles or the like, and when again extending the shiftable plug an
open flow section of the hose conduit could be obtained with a
minimum risk of contamination. In the known arrangement, the hose
conduit leading to the patient was never closed. In contrast
thereto, the openings, through which the plug has been shifted and
via which the flow connection with the hose length connected to the
second coupling member had been established, had, in the retracted
position of the plug, their ends within the sponge member soaked
with the disinfectant, which resulted, on the one hand, in the risk
of sucking disinfectant from this sponge member into the conduit
leading to the patient and, on the other hand, resulted in the
possibility that in case of a corresponding pressure difference
body fluids could be pressed into the sponge member.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a device of the
initially mentioned type for providing the possibility to tightly
close the conduit leading to the patient simultaneously with the
retracting movement of the plug being effected when interchanging
the infusion equipment. For solving this task, the arrangement
according to the invention consists, in principle, in that the
hollow plug consists of two parts concentrically arranged one
relative to the other, noting that both parts of the plug are
adapted for being axially shiftable one relative to the other or in
common and that, in encased position of the parts of the plug, the
outflow opening of the plug is closable. On account of the plug
being a bipartite plug, there is provided the possibility to close
the conduit in its part connected to the plug either by relative
rotation of both plug parts one against the other or by axially
shifting one plug part relative to the other plug part. In this
case, it is sufficient to design the corresponding connecting bores
such that they are in mutual alignment in the operating position
and thus provide for an open flow through the conduit and that they
slide, in the retracted position, one past the other in a manner
providing a tight seal. This can, in a simple manner, be achieved
if the outer part of the plug is supported for being shifted
together with the inner part of the plug and is supported on the
inner part of the plug for being rotatable. In such an arrangement,
an open connection between the inner plug part and the outer plug
part can be obtained in a predetermined rotated position, to the
latter whereas such an open connection can be interrupted in a
rotated position corresponding to the position for retracting the
plug. This is in a simple manner achieved if the inner part of the
plug has channels or grooves extending in axial direction and the
outer part has radial perforations opening into the channels or
grooves of the inner part in one relative rotated position between
the outer part and the inner part. Such channels or grooves
extending in the longitudinal direction of the inner part of the
plug form axially extending flow channels which can, in dependence
on the rotated position of the outer part of the plug, be brought
in aligned position with the corresponding perforations or,
respectively, radial flow passages of the outer part of the plug,
whereas the radial flow passages of the outer part of the plug can
be covered by the material of the inner plug in a non-aligned
rotated position at the grooves and perforations. If one plug part
is axially shiftable relative to the other plug part, there must be
provided a corresponding circumferential seal and there must be
reached, when shifting the outer part of the plug over the inner
part of the plug, an end position in which the flow passages of the
outer part are closed by means of sealing elements provided on the
circumference of the inner part of the plug.
For the purpose of further increasing the safety against
contamination and in particular also the safety against dragging
disinfectant into the blood path, the arrangement is advantageously
such that an absorbing insert, in particular an annular disc
consisting of foamed material, is provided as a stripper disc
within the second coupling member carrying the perforable
diaphragm. Such a stripper disc absorbs any disinfectant, present
on the outer surface of the plug, and in consideration of the
circumstance that this stripper disc is supported in the second
coupling member, it is made sure that when interchanging the
infusion equipment always fresh stripper discs are used together
with the diaphragm to be perforated. In this case, the arrangement
can in an advantageous manner be such that the perforable diaphragm
or diaphragms, the stripper disc as well as, optionally, the
sealing disc are arranged within a common constructional part which
can be locked with the second coupling member, to assure that the
stripper disc and the diaphragm are interchanged in common.
In the known construction of the coupling, the remaining residual
volume of air contained, if at all, was comparatively small, but on
account of the construction of the known constructional parts small
residual amounts of air remain within the conduit and subsequently
enter the blood path via the tubular plug together with the fluid
supplied via the hose line. For the purpose of reliably preventing
any dragging of such residual amounts of air into the blood path,
the arrangement in the invention is advantageously such that the
second coupling member has a connecting piece for the second hose
length eccentrically arranged relative to the shifting path of the
plug and has an air venting opening coaxially arranged relative to
the shifting path of the plug adapted to be closed by the plug in
the coupled position. When connecting a new infusion bottle to such
a second coupling member, the residual air volume can first be
forced out through the air venting opening, and the central air
venting opening can be tightly closed by the plug itself in the
operating position of the plug. For this purpose, the arrangement
is advantageously such that the front end of the outer part of the
plug carries an axial sealing protrusion tightly entering into the
air venting opening of the second coupling member in the coupled
position. For the purpose of facilitating ventilation of the fluid
when effecting coupling to the second coupling member and, in
particular, for preventing the fluid from soaking the stripper disc
provided on the second coupling member and thus from making the
stripper disc inoperative, the arrangement is advantageously such
that the second coupling member has, in addition to the perforable
diaphragm located opposite the connecting piece for the second hose
length and in addition to the stripper disc, a further perforable
diaphragm or a sealing disc separating the space, into which the
connection for the second hose length, opens from the stripper
disc. In this manner, the stripper disc is maintained in a dry
condition and is maintained absorbable for the disinfectant
adhering, if at all, on the outer surface of the plug.
For the purpose of assuring reliable connecting of the parts of the
plug, the arrangement is advantageously such that the inner part of
the plug has, at its end located opposite the outflow openings of
the outer part, claws embracing a base disc of the outer part. Such
type of connection between both parts of the plug reliably provides
for relative rotation of the outer part of the plug on the inner
part of the plug without detracting from the stability of the
connection in the axial direction. For the purpose of
simultaneously obtaining a great sealing effect, there can be
provided in such an arrangement a corresponding seal within the
area of this force-locking connection against axial shifting
movement, for which purpose the arrangement is advantageously such
that the inner part of the plug has, within the area of the claws,
a conical sealing surface for engagement with a hollow-conical
cooperating surface provided within or in proximity of the base
part of the outer part of the plug. In this manner, there can be
produced in a simple manner a bipartite plug of high precision,
good sealing properties and facilitated rotatability of the outer
part of the plug relative to the inner part of the plug.
When using conical sealing surfaces, there exists, however, on
frequent use the risk of jamming of the conical sealing surfaces,
because primarily synthetic plastics materials are used for the
inner part as well as for the outer part. Jamming results in an
increase of the force to be exerted for rotating the outer part on
the inner part of the plug, and for this reason the arrangement is
advantageously such that the outer part of the plug is supported on
the cone of the inner part with interposition of an annular seal,
in particular a lip seal. In this manner, there is assured over
long operating periods an exact seal as well as ease of
rotation.
For the purpose of providing the possibility of rotating the outer
part of the plug on the inner part of the plug, the arrangement is
advantageously such that the outer part has a radial actuating
protrusion for the manipulating rotating movement around the axis
of the inner part, the radial actuating protrusion being guided
within a guide slot of the first coupling member for shafting in
the axial direction and in the circumferential direction of the
first coupling member in the predetermined axially shifted
position. The slot-like guide means simultaneously assures that the
locked position, i.e. the rotated position of the outer part of the
plug relative to its inner part intended for obstructing the free
flow through the exit openings of the outer part of the plug, is
positively reached when retracting the plug. A reliable closure of
the conduit connected with the patient is thus automatically
obtained when retracting the plug for the purpose of interchanging
the infusion equipment.
BRIEF DESCRIPTION OF THE DRAWING
In the following, the invention is further explained with reference
to an embodiment schematically shown in the drawing wherein:
FIG. 1 is a schematic axial cross-sectional view of the inventive
coupling;
FIG. 2 is an enlarged cross-sectional view of the inner part of the
plug of a device according to FIG. 1:
FIG. 3 is a cross-sectional view taken along lien III--III of FIG.
2;
FIG. 4 is an axial cross-sectional view through the outer part of
the plug;
FIG. 5 is a top plan view in direction of the arrow V of FIG. 4;
and
FIG. 6 is, in a reduced scale, a side elevational view in direction
of the arrow VI of FIG. 1, which shows the guide slot for the
relative rotation of the outer part of the plug on the inner part
of the plug.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In FIG. 1 there is shown a first coupling member 1 having a plug 2
being shiftable in the axial direction, noting that this plug 2
consists of an outer part 3 and of an inner part 4. A second
coupling member 5 is connected to the first coupling member 1 and
has a connecting piece 7 located eccentrically relative to the axis
6 of the plug or, respectively, the shifting path of the plug and
having connected thereto a hose line leading to an infusion
equipment. Centrally and on axis 6 there is provided on the second
coupling member 5 an air ventilation bore 8. When shifting the plug
2 in the axial direction, the plug 2 is first moved through a first
insert member of absorbing material permanently soaked by a
disinfectant. proceeding in the axial direction, there is provided
a second interchangeable absorbing insert member 10, in which the
disinfectant can be replenished for assuring a reliable
disinfection. Within the second coupling part 5, there is provided
a perforable diaphragm 11 as well as a further absorbing insert
member 12 in the manner of a stripping disc which wipes off and
absorbs any material adhering on the outer surface of the plug
2.
When connecting an infusion bottle to the connecting piece 7, air
ventilation can be achieved by introducing into the space 13 the
entering fluid until the fluid flows out of the air ventilating
bore 8. For the purpose of making sure that the stripping insert
member 12 does not come, during such scavenging procedure for
removing residual air, in contact with the fluid and is thus not
soaked with fluid and thus maintains its absorbing capacity, there
is provided a sealing insert 14, which forms a central closure
means like a lip seal. In place of such a sealing insert 14 there
can of course be provided a further perforable diaphragm being
analog to the diaphragm 11, noting that the diaphragm 11, the
stripper disc 12 as well as the sealing disc 14 are held by a
common constructional part 15 which can be locked with the second
coupling member 5.
For the purpose of assuring a tight closure of the conduit leading
to the patient and being connected to the plug via the connecting
piece 16 in the retracted position of the plug shown in FIG. 1, the
outer part 3 of the plug 2 is provided with a radial actuating
protrusion 17 extending through a guiding slot 27 in the wall of
the first coupling member 1. The inner plug part 4 has at least one
radial bore 18 in connection with the axial opening in connecting
piece 16 and channels 20 in inner part 4. Radial passages 19 in
outer part 3 are tightly engaged against the outer surface of inner
part 4 of the plug 2 in the rotated position shown in FIG. 1, so
that the radial passages 19 of the outer part 3 of the plug are, in
the position shown in FIG. 1, sealed against the radial bore 18 of
the inner part 4. This is further made clear in the FIGS. 2 and
3.
In FIGS. 2 and 3, the inner part 4 of the bipartite plug 2 is shown
in an enlarged scale. The inner plug 4 has, as is shown in FIG. 3,
channels 20 extending in the axial direction and adapted to be
brought into alignment with the radial passages 19 of the outer
part 3 of the plug in a predetermined relative rotated position.
The inner part 4 of the plug is connected with a base member 21
provided with claws 22 for locking with the outer part 3 of the
plug 2. The connecting piece 16 of the conduit leading to the
patient opens, via the base member 21, into the radial channels 18
of the plug, the radial channels again opening into the axially
extending space delimited by the channels 20 of the inner part of
the plug 4 and the inner wall of the outer part 3 of the plug. The
base member is further provided with a conical sealing surface 23
which, after putting the outer part of the plug into a rest
position is secured against axial shifting movement by the claws 22
of the base member 21, forming a sealing surface relative to the
outer part 3 of the plug.
In the representation according to FIGS. 4 and 5, the outer part 3
of the plug is shown in an enlarged scale, noting that there are
again shown the radial bores 19, via which fluid can be introduced
into the conduit leading to the patient. For this purpose there
must, however, first be perforated diaphragm 11 of the second
coupling member 5 and the plug must first be shifted in the axial
direction and subsequently be rotated by means of the radial
actuating protrusion 17 for the purpose of establishing the open
connection between the radial bores 19 and the axially extending
channels 20 of the inner plug. The outer part 3 of the bipartite
plug has on its base member again conical sealing surfaces 24
cooperating with the conical sealing surfaces 23 of the inner plug
in a sealing manner when put onto the inner part 4 of the plug.
Within the same area, the outer part 3 of the plug carries a flange
25 embraced in a locking manner by the claws 22 of the inner part
4, so that relative swivellability is reliably maintained but axial
separation of the outer part 3 from the inner part 4 is not
possible without special measure.
The front end of the outer part 3 of the plug 2 has a sealing
protrusion 26 which in the end position of the shifting path of the
plug 2 is inserted into the air ventilating opening 8 of the second
coupling member 5 and thus tightly closes that opening.
The guiding slot for the radial actuating protrusion 17 is clearly
shown in the representation according to FIG. 6 as guiding groove
27 extending in a first partial range in the axial direction of the
first coupling member 1. After having reached the end position of
the plug, in which position the tip of the outer part 3 cooperates
via the sealing protrusion 26 with the air ventilating opening 8,
the radial actuating protrusion can be moved in the circumferential
direction along the last oblique partial range 28 of the guiding
groove, whereby the radial bores 19 of the outer part 3 are
swivelled into an aligned position with the axial channels 20 of
the inner plug 4 and the open connection between the connecting
piece 7 of the coupling member 5 and the connecting piece 16 of the
plug 2 is established. Simultaneously, the tight closure of the air
ventilating opening 8 is improved.
In FIGS. 1 and 4 there can further be seen an annular seal 29
provided with a sealing lip. Such an annular seal 29 reliably
provides for the free swivellability of the outer part 3 of the
plug 2 on the inner part 4 without, detracting from a tight
seal.
In FIG. 3, there is further shown recesses 30 on the circumference
of the base member. These recesses 30 cooperate with corresponding
protrusions, not shown in the drawing, provided on the inner
circumference of the first coupling member 1 for locking the inner
part 4 of the plug 2 against rotation, so that when rotating the
outer part 3 by actuating the radial actuating protrusion 17 the
inner part 4 reliably remains in its rotated position for assuring
free flow through the flow passages in the operating position.
* * * * *